Validity and reliability of the behavioral signs of respiratory instability (BSRI) © scale during activity for infants with bronchopulmonary dysplasia

OBJECTIVE

There is no reliable evidence on how best to evaluate the overall status of infants with severe forms of bronchopulmonary dysplasia (BPD). The Behavioral Signs of Respiratory Instability (BSRI) scale was developed as an objective measure of developmental capacity during occupational and physical therapy sessions. The purpose of this study was to determine the psychometric properties of the BSRI Scale.

STUDY DESIGN

The BSRI and Respiratory Severity Score (RSS) were compared for 25 infants with BPD and 15 infants without BPD. A cross-sectional design was used to test inter-rater reliability among 10 NICU occupational and physical therapists. A prospective cohort design was used to evaluate validity.

RESULTS

The BSRI demonstrated good to excellent inter-rater reliability (ρ = 0.47-0.91) and was strongly correlated with RSS (ρ = -0.77, p < 0.001; concurrent validity).

CONCLUSION

The BSRI Scale has preliminary psychometric support. Standardized measures like the BSRI may provide accurate, objective data that can improve care planning within interdisciplinary teams that supports brain growth and potentially improves neurodevelopment.

Erysipelothrix rhusiopathiae Infection Associated with Swollen Head Syndrome in a Broiler Breeder Flock in North Georgia

An unusual case of swollen head syndrome in a 55-wk-old broiler breeder flock was identified in north Georgia in the summer of 2019. The presenting complaint was elevated mortality and visibly swollen heads. Necropsy of affected birds on the farm primarily revealed signs of bacterial septicemia, with few large scab lesions near the vent area. Bacterial culture analysis identified multiple organisms, but the primary organism of interest was identified as Erysipelothrix rhusiopathiae, cultured from affected liver, lung, sinuses, and one swollen wattle of birds in the affected house. Histopathologic analysis identified gram-positive rod-shaped bacteria in the spleen and liver (consistent with bacterial septicemia) confirmed with special staining (Brown & Hopps Gram stain). These organisms were noted to be consistent with E. rhusiopathiae; E. rhusiopathiae infection in broiler breeder chickens is a rare occurrence and is primarily associated with turkeys and/or swine production systems.

Campylobacter hepaticus in the Production Environment and Stagnant Water as a Potential Source of C. hepaticus Causing Spotty Liver Disease in Free-Range Laying Hens in Georgia, United States

Spotty liver disease (SLD) has emerged as an important cause of disease in egg-producing flocks in countries such as the United Kingdom and Australia and has emerged in the United States. The organisms implicated in SLD include Campylobacter hepaticus and, more recently, Campylobacter bilis. These organisms have been found to cause focal lesions on the livers of infected birds. Campylobacter hepaticus infection results in reduced egg production, decreased feed consumption resulting in reduced egg size, and increased mortality of highly valuable hens. In the fall of 2021, birds from two flocks (A and B) of organic pasture-raised laying hens were submitted to the Poultry Diagnostic Research Center at the University of Georgia with a history suspicious of SLD. Postmortem examination of Flock A found 5/6 hens had small multifocal lesions on the liver and were PCR positive for C. hepaticus from pooled swab analysis of samples of the liver and gall bladder. Necropsy of Flock B found 6/7 submitted birds had spotty liver lesions. In pooled bile swabs, 2/7 hens from Flock B were also PCR positive for C. hepaticus. A follow-up visit to Flock A was scheduled 5 days later, as well as a visit to a flock where SLD has not been reported (Flock C), which was used as a comparative control. Samples of the liver, spleen, cecal tonsil, ceca, blood, and gall bladder were collected from six hens per house. Additionally, feed, water nipples, and environmental water (stagnant water outside the house) were collected from the affected farm and the control farm. To detect the organism, all samples collected were subjected to direct plating on blood agar and enrichment in Preston broth with incubation under microaerophilic conditions. After multiple phases of bacterial culture purification from all samples, single bacterial cultures displaying characteristics of C. hepaticus were tested by PCR to confirm identity. From Flock A, liver, ceca, cecal tonsils, gall bladder, and environmental water were PCR positive for C. hepaticus. No positive samples were detected in Flock C. After another follow-up visit, 10 wk later, Flock A was PCR positive for C. hepaticus from gall bladder bile and feces and one environmental water sample displayed a weak positive reaction for C. hepaticus. Flock C was PCR negative for C. hepaticus. To gain more knowledge about C. hepaticus prevalence, a survey of 6 layer hens from 12 different layer hen flocks between the ages of 7 to 80 wk, raised in different housing systems, were tested for C. hepaticus. The 12 layer hen flocks were culture and PCR negative for C. hepaticus. Currently, there are no approved treatments for C. hepaticus and no vaccine is available. The results of this study suggest that C. hepaticus may be endemic in some areas of the United States, and free-range laying hens may be exposed from the environment/stagnant water in areas where they range.

Hemorrhagic Hepatopathy in Broiler Breeder Pullets: Gross and Microscopic Pathology and Factors Associated with Incidence

Hemorrhagic hepatopathy is a syndrome reported in layer pullets resulting in mortality and lesions including hepatic, splenic, and intestinal necrosis; hepatic and splenic enlargement; hemorrhages; amyloidosis of the muscle, spleen, and liver; accumulation of noncoagulated hemorrhagic fluid in the coelom; and frequently, granulomatous myositis at bacterin injection sites. The syndrome is characterized in the literature in table egg layer pullets and is thought to be associated with the administration of bacterin vaccines, namely, frequently Salmonella enterica subsp. enterica bacterins. Hemorrhagic hepatopathy is recognized by industry veterinarians as also occurring infrequently in broiler breeder pullets in the United States. As the condition is likely due to an inflammatory process in response to bacterial lipopolysaccharide inoculation, it is important to characterize both the pathologic changes and predisposing factors for the condition in broiler breeds, which are immunologically different from table egg layer breeds. In this study, we characterize the gross and microscopic lesions observed in a series of diagnostic laboratory cases of hemorrhagic hepatopathy in broiler breeder pullets and suggest a possible pathophysiology for the condition. Additionally, we report results from a case survey of the United States broiler industry that suggest that the condition is due to a reaction to bacterin vaccination and that certain bacterin products may predispose pullet flocks to develop the condition. Although further research is indicated, these findings establish hemorrhagic hepatopathy as a pathologic condition of broiler breeder pullets and may aid in the diagnosis and prevention of the syndrome.

P1115Cardiac SABR for ventricular tachycardia - initial UK experience

OnBehalf

United Kingdom Cardiac SABR consortium

Background

Stereotactic Ablative Body Radiotherapy (SABR) is a novel non-invasive treatment for Ventricular Tachycardia (VT) refractory to standard catheter ablation. 3 UK hospitals have started compassionate use cardiac SABR programmes, and are working in close collaboration.

Purpose

To report initial UK experience for treatment of refractory VT with cardiac SABR.

Methods

All patients had undergone prior unsuccessful invasive ablation with VT recurrence despite anti-arrhythmic drug (AAD) use. High-resolution CT imaging with 3D reconstruction was combined with 12 lead ECGs of VT and prior invasive +/- non-invasive electrophysiology mapping data to define a cardiac target. Treatment margins were modified to account for cardiac/respiratory motion and to minimise off target treatment to other organs as per clinical SABR practice. Single fraction high dose treatment (20-25 Gy) was delivered by CT guided Linear Accelerator. Patients were assessed regularly with clinical review and remote device monitoring.

Results

3 patients have been treated so far with aetiologies of prior myocarditis, non-ischaemic dilated cardiomyopathy and ischaemic cardiomyopathy. All patients successfully received planned SABR treatment in &lt;1 hour with no peri-procedural complications. Current follow up is to 4 months. Clinical course was variable – patient 1 had a flare of VT post-SABR requiring temporary escalation of AADs before VT was suppressed, patient 2 had initial suppression of VT but died from decompensated heart failure with further VT after 4 weeks, patient 3 had further VT with a different exit site and underwent repeat invasive ablation and escalated AAD use to achieve VT suppression.

Conclusions

Cardiac SABR shows promise for VT control, but further experience and trials are needed. Integration of imaging and electrophysiology data to generate accurate targets appears critical. The effect of SABR seems to develop over several weeks after therapy. Patient selection and timing of SABR delivery is important with acknowledgement that competing causes of death exist in patients with refractory VT entering a compassionate use program.

Abstract Figure. Example SBRT plan

664Local catheter impedance drop during pulmonary vein isolation predicts conduction block in patients with paroxysmal atrial fibrillation: initial results of the LOCALIZE clinical trial

Funding Acknowledgements

Boston Scientific

Background

Radiofrequency (RF) catheter ablation for pulmonary vein isolation (PVI) requires resistively heating cardiac tissue to create conduction block. Creation of an RF lesion results in an impedance drop and the magnitude of this drop depends on the temperature and amount of myocardium being heated. Pre-clinical and clinical evaluation of an advanced local impedance (LI) metric found that greater LI drops were indicative of more effective lesion formation.

Purpose

To evaluate whether LI drop is associated with conduction block after first pass encirclement of the PVs in patients with paroxysmal AF.

Methods

LOCALIZE is an ongoing, single-arm, multi-center clinical trial (clinicaltrials.gov NCT03232645). LOCALIZE consists of an index PVI procedure (results presented here) and a 3-month follow-up mapping procedure. In the index procedure, electroanatomical maps of the left atrium were created and ipsilateral PVs were divided into 8 anatomical segments (n = 16 per patient). PVI was performed using point-by-point ablation with blinding of operators to LI. Following initial encirclement and a 20-minute wait period, coronary sinus-paced electroanatomical maps were created to identify gaps within anatomical segments. Gaps were annotated on the map and subsequently ablated. Mean LI drop within each segment was calculated offline as an estimate of regional RF energy delivery (Figure - Left). The diagnostic accuracy of LI drop for predicting segment block was assessed using receiver operating characteristic (ROC) analysis in segments with inter-lesion spacing ≤6mm.

Results

Forty-seven patients with paroxysmal AF underwent PVI at 5 centers (age 62 ± 11 years, male 55.3%). All patients left the index procedure with all PVs isolated. When blinded to LI (n = 3,064 ablations), median baseline LI was 106 (IQR: 97-115) Ω and median LI drop was 18.4 (12.7-24.9) Ω. After first pass encirclement, blocked segments had a significantly larger LI drop (20.2 [14.6-26.0] Ω) than segments with gaps (10.6 [6.9-15.1] Ω, p &lt; 0.01, Figure - Right). The association between LI drop and block was further evaluated along anatomical anterior/posterior wall thickness differences. Anterior block segments were found to have significantly larger LI drops (21.0 [15.9-27.2] Ω) than posterior block segments (16.6 [12.7-23.7] Ω, p &lt; 0.01). ROC analysis of segments with inter-lesion spacing ≤6mm identified optimal LI cut-off values of 16Ω in anterior segments and 11Ω posteriorly, which had positive predictive values for conduction block of 95.6% and 96.7%, respectively.

Conclusions

The magnitude of LI drop is predictive of acute PVI segment conduction block in patients with paroxysmal AF. The thinner posterior wall required smaller LI drops for block compared to the thicker anterior wall. With inter-lesion spacing of ≤6mm, reaching a LI drop of ≥16Ω anteriorly and ≥11Ω posteriorly was highly predictive of acute segment block in de novo PVI.

Abstract Figure. Local impedance drop in de novo PVI

Simultaneous Determination of Multiple Tetracycline Residues in Milk by Metal Chelate Affinity Chromatography: Collaborative Study

To meet federal and state regulatory needs, a liquid chromatographic (LC) method with ultraviolet (UV) detection was developed for determination of 7 tetracyclines at 30 ng/mL in milk. Raw milk samples are defatted, acidified, and centrifuged to remove proteins, and tetracyclines are specifically absorbed from the milk by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns. Tetracyclines are removed from these columns with EDTA-containing buffer, and extracts are further cleaned by ultrafiltration. Finally, extracts are concentrated and analyzed simultane ously by using on-line concentration. This method was validated in a collaborative study that involved 11 laboratories, including the authors’ laboratory. Each laboratory was asked to prepare and analyze known control and fortified milk samples, as well as 18 coded blind samples. Eight laboratories completed all analyses. Average interlaboratory recoveries for the known fortified samples ranged from 59% (methacycline at 15 ng/mL) to 78% (oxytetracy cline at 60 ng/mL). Average recovery for each of 7 residues at 30 ng/mL were between 60 and 110%, meeting single-residue guidelines for accuracy set by the U.S. Food and Drug Administration. Reproducibility relative standard deviation (RSDR) for the known fortified samples varied from 11 to 39%, with 6 of 7 residues at the 30 ng/mL level having RSDR values at or below 20%. Seven of 8 laboratories correctly identified blind control milk samples and all 28 residues present in blind samples. The metal chelate affinity—LC method for determination of multiple tetracycline residues in milk has been adopted first action by AOAC INTERNATIONAL.

Effect of Infection with a Mesogenic Strain of Newcastle Disease Virus on Infection with Highly Pathogenic Avian Influenza Virus in Chickens

Little is known on the interactions between avian influenza virus (AIV) and Newcastle disease virus (NDV) when coinfecting the same poultry host. In a previous study we found that infection of chickens with a mesogenic strain of NDV (mNDV) can reduce highly pathogenic AIV (HPAIV) replication, clinical disease, and mortality. This interaction depended on the titer of the viruses used and the timing of the infections. To further explore the effect of mNDV infectious dose in protecting chickens against HPAIV infection, 2-wk-old birds were inoculated with different doses of mNDV (10(4), 10(6), or 10(7) 50% embryo infective dose [EID50]) 3 days before inoculation with a HPAIV (10(5) or 10(6) EID50). Although birds coinfected with the higher mNDV doses (10(6) or 10(7)) survived for longer than birds inoculated only with HPAIV (10(5)), we did not observe the same protection with the lower dose of mNDV (10(4)) or when given the higher dose of HPAIV (10(6)), indicating that the relation between the titer of the two coinfecting viruses is determinant in the outcome. In a similar experiment, a higher number of 4-wk-old birds survived, and for longer, even when given higher HPAIV doses (10(6.3) and 10(7.3) EID50). In addition, we also examined the duration of protection provided by mNDV (10(7) EID50) on a HPAIV infection. Five-week-old chickens were inoculated with mNDV followed by inoculation with 10(6) EID50 of an HPAIV given at 2, 4, 6, or 9 days after the mNDV. HPAIV replication was affected and an increase in survival was found in all coinfected groups when compared to the HPAIV single-inoculated group, but the mortality in coinfected groups was high. In conclusion, previous inoculation with mNDV can affect HPAIV replication in chickens for at least 9 days, but this viral interference is titer dependent.

Pathogenicity and Transmission of H5 and H7 Highly Pathogenic Avian Influenza Viruses in Mallards

Wild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 (Gs/GD) lineage during 2005, 2010, and 2014, but dispersion by wild waterfowl has not been implicated with spread of other HPAI viruses. To better understand why Gs/GD H5 HPAI viruses infect and transmit more efficiently in waterfowl than other HPAI viruses, groups of mallard ducks were challenged with one of 14 different H5 and H7 HPAI viruses, including a Gs/GD lineage H5N1 (clade 2.2) virus from Mongolia, part of the 2005 dispersion, and the H5N8 and H5N2 index HPAI viruses (clade 2.3.4.4) from the United States, part of the 2014 dispersion. All virus-inoculated ducks and contact exposed ducks became infected and shed moderate to high titers of the viruses, with the exception that mallards were resistant to Ck/Pennsylvania/83 and Ck/Queretaro/95 H5N2 HPAI virus infection. Clinical signs were only observed in ducks challenged with the H5N1 2005 virus, which all died, and with the H5N8 and H5N2 2014 viruses, which had decreased weight gain and fever. These three viruses were also shed in higher titers by the ducks, which could facilitate virus transmission and spread. This study highlights the possible role of wild waterfowl in the spread of HPAI viruses.

IMPORTANCE

The spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the Gs/GD lineage by migratory waterfowl is a serious concern for animal and public health. H5 and H7 HPAI viruses are considered to be adapted to gallinaceous species (chickens, turkeys, quail, etc.) and less likely to infect and transmit in wild ducks. In order to understand why this is different with certain Gs/GD lineage H5 HPAI viruses, we compared the pathogenicity and transmission of several H5 and H7 HPAI viruses from previous poultry outbreaks to Gs/GD lineage H5 viruses, including H5N1 (clade 2.2), H5N8 and H5N2 (clade 2.3.4.4) viruses, in mallards as a representative wild duck species. Surprisingly, most HPAI viruses examined in this study replicated well and transmitted among mallards; however, the three Gs/GD lineage H5 HPAI viruses replicated to higher titers, which could explain the transmission of these viruses in susceptible wild duck populations.

Challenges, successes and opportunities for reducing readmissions in a referral-based children's hospital NICU

AIM

To evaluate readmission data in a level IV neonatal intensive care unit (NICU) to identify patient characteristics and process failures which serve as drivers for readmission.

METHODS

Our center is a primary referral center in Central and Southeast Ohio, providing us a unique opportunity to evaluate readmissions. We studied our current discharge process, caregiver perception of discharge readiness, parental comfort and the pre-discharge and post-discharge characteristics of infants.

RESULTS

Our readmission rate during the 4 year period has remained stable at 9.8%. 74% of the caregivers rated that their perception of their baby's medical readiness for discharge was good to excellent. Duration of hospitalization and public insurance coverage (Medicaid) were significant risk factors for readmission (p = 0.00). In our setting, the majority of the patients are readmitted through the emergency department and nearly half of all readmissions were for 3 or fewer days. Patients discharged from our Comprehensive Center for BPD had similar readmission rate despite characteristics which should increase their readmission rate.

CONCLUSIONS

Readmission rate is a poor indicator of the quality of care provided in the NICU. In addition to patient factors such as longer length of stay and Medicaid, our data suggests that preventing readmission depends on having systems in place to help families cope with transition of care after discharge.

Previous infection with virulent strains of Newcastle disease virus reduces highly pathogenic avian influenza virus replication, disease, and mortality in chickens

Highly pathogenic avian influenza virus (HPAIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide and produce co-infections especially in areas of the world where both viruses are endemic; but little is known about the interactions between these two viruses. The objective of this study was to determine if co-infection with NDV affects HPAIV replication in chickens. Only infections with virulent NDV strains (mesogenic Pigeon/1984 or velogenic CA/2002), and not a lentogenic NDV strain (LaSota), interfered with the replication of HPAIV A/chicken/Queretaro/14588-19/95 (H5N2) when the H5N2 was given at a high dose (10^6.9 EID₅₀) two days after the NDV inoculation, but despite this interference, mortality was still observed. However, chickens infected with the less virulent mesogenic NDV Pigeon/1984 strain three days prior to being infected with a lower dose (10^5.3–5.5 EID₅₀) of the same or a different HPAIV, A/chicken/Jalisco/CPA-12283-12/2012 (H7N3), had reduced HPAIV replication and increased survival rates. In conclusion, previous infection of chickens with virulent NDV strains can reduce HPAIV replication, and consequently disease and mortality. This interference depends on the titer of the viruses used, the virulence of the NDV, and the timing of the infections. The information obtained from these studies helps to understand the possible interactions and outcomes of infection (disease and virus shedding) when HPAIV and NDV co-infect chickens in the field.

Experimental co-infections of domestic ducks with a virulent Newcastle disease virus and low or highly pathogenic avian influenza viruses

Infections with avian influenza viruses (AIV) of low and high pathogenicity (LP and HP) and Newcastle disease virus (NDV) are commonly reported in domestic ducks in many parts of the world. However, it is not clear if co-infections with these viruses affect the severity of the diseases they produce, the amount of virus shed, and transmission of the viruses. In this study we infected domestic ducks with a virulent NDV virus (vNDV) and either a LPAIV or a HPAIV by giving the viruses individually, simultaneously, or sequentially two days apart. No clinical signs were observed in ducks infected or co-infected with vNDV and LPAIV, but co-infection decreased the number of ducks shedding vNDV and the amount of virus shed (P<0.01) at 4 days post inoculation (dpi). Co-infection did not affect the number of birds shedding LPAIV, but more LPAIV was shed at 2 dpi (P<0.0001) from ducks inoculated with only LPAIV compared to ducks co-infected with vNDV. Ducks that received the HPAIV with the vNDV simultaneously survived fewer days (P<0.05) compared to the ducks that received the vNDV two days before the HPAIV. Co-infection also reduced transmission of vNDV to naïve contact ducks housed with the inoculated ducks. In conclusion, domestic ducks can become co-infected with vNDV and LPAIV with no effect on clinical signs but with reduction of virus shedding and transmission. These findings indicate that infection with one virus can interfere with replication of another, modifying the pathogenesis and transmission of the viruses.

Early extubation attempts reduce length of stay in extremely preterm infants even if re-intubation is necessary

OBJECTIVE

Prolonged mechanical ventilation in the extremely premature infant is associated with the development of bronchopulmonary dysplasia (BPD). Clinically, the decision to extubate the extremely low birth weight (ELBW) infant can be difficult. There is continued debate regarding whether it is better for an ELBW infant to remain on the ventilator or to extubate to nasal constant positive airway pressure (nCPAP). It has also been argued that repeated intubations may be detrimental to ELBW infants. We tested the hypothesis that earlier extubation attempts would decrease length of hospital stay and BPD.

STUDY DESIGN

A database maintained on infants born at <27 completed weeks gestation admitted to our all referral NICU for a 36 month period was queried (n = 224).

RESULTS

Day of life (DOL) of the first extubation attempt was inversely correlated with birth weight (p <  0.001) and gestational age (p <  0.01). The DOL of the 1st extubation attempt correlated with the need for re-intubation (p <  0.001), but not with mortality (p = 0.27). In survivors, earlier DOL of 1st extubation attempt was associated with shorter LOS (p <  0.001). Earlier DOL of the 1st extubation attempt was associated with less need for supplemental oxygen (p <  0.001) at 36 weeks CGA, while re-intubation was not (p = 0.50).

CONCLUSION

In our cohort of extremely premature infants, the earlier the first extubation attempt the sooner the patient was discharged home and the less likely to develop BPD. Our study suggests that extubation should not be delayed in extremely premature infants due to fears of need for re-intubation.

Incidence of central line related/associated bloodstream infections in an acute hospital

Bloodstream infection related to a central venous catheter in the intensive care unit is a substantial clinical and economic problem. The aim of the study was to examine the incidence of central line related bloodstream infections and central line associated bloodstream infections in Our Lady of Lourdes Hospital, Drogheda, during a six month period, using an active patient based prospective surveillance method. CLRBSI rate in ICU/HDU was 0.93/1000 central line days. There was no CLABSI identified in the studied time period. However, further interventions are needed, particularly with CVC care bundle. Also, the implementation of 2% chlorhexidin in 70% isopropylalcohol use for skin asepsis, which is recommended by the Irish national guidelines, would be beneficial.

Empowerment programme for parents of extremely premature infants significantly reduced length of stay and readmission rates

AIM

Extremely premature infants experience long hospitalisation and high readmission rates within 30 days of discharge. This quality control investigation retrospectively explored the impact of the Creating Opportunities for Parent Empowerment (COPE©) programme on these rates in an all referral, Level-IV small baby intensive care unit setting.

METHODS

The parents of 303 extremely premature infants participated in the study. Of those, 135 were admitted before the implementation of COPE© and served as baseline historical controls, and the remaining 168 neonates received the intervention. Length of stay and readmission rates were analysed using parametric and nonparametric tests. Additional analyses were used to compare the two groups in terms of gestational age, birthweight and other acuity measures.

RESULTS

Neonates who received COPE© required significantly reduced lengths of stay than the control neonates (COPE© 127.1 ± 55.8 days vs. control 139.6 ± 61.9 days, p < 0.05) and significantly lower readmission rates (COPE© 23.9% vs. control 13.2%, p = 0.05).

CONCLUSION

The COPE© programme promoted active parental engagement in the unit and significantly reduced hospital stays and readmission rates. Future interventions should identify the specific components of the programme that support the parents of extremely premature infants during the various phases of hospitalisation.

Suboptimal protection against H5N1 highly pathogenic avian influenza viruses from Vietnam in ducks vaccinated with commercial poultry vaccines

Domestic ducks are the second most abundant poultry species in many Asian countries including Vietnam, and play a critical role in the epizootiology of H5N1 highly pathogenic avian influenza (HPAI) [FAO]. In this study, we examined the protective efficacy in ducks of two commercial H5N1 vaccines widely used in Vietnam; Re-1 containing A/goose/Guangdong/1/1996 hemagglutinin (HA) clade 0 antigens, and Re-5 containing A/duck/Anhui/1/2006 HA clade 2.3.4 antigens. Ducks received two doses of either vaccine at 7 and at 14 or 21 days of age followed by challenge at 30 days of age with viruses belonging to the HA clades 1.1, 2.3.4.3, 2.3.2.1.A and 2.3.2.1.B isolated between 2008 and 2011 in Vietnam. Ducks vaccinated with the Re-1 vaccine were protected after infection with the two H5N1 HPAI viruses isolated in 2008 (HA clades 1.1 and 2.3.4.3) showing no mortality and limited virus shedding. The Re-1 and Re-5 vaccines conferred 90-100% protection against mortality after challenge with the 2010 H5N1 HPAI viruses (HA clade 2.3.2.1.A); but vaccinated ducks shed virus for more than 7 days after challenge. Similarly, the Re-1 and Re-5 vaccines only showed partial protection against the 2011 H5N1 HPAI viruses (HA clade 2.3.2.1.A and 2.3.2.1.B), with a high proportion of vaccinated ducks shedding virus for more than 10 days. Furthermore, 50% mortality was observed in ducks vaccinated with Re-1 and challenged with the 2.3.2.1.B virus. The HA proteins of the 2011 challenge viruses had the greatest number of amino acid differences from the two vaccines as compared to the viruses from 2008 and 2009, which correlates with the lesser protection observed with these viruses. These studies demonstrate the suboptimal protection conferred by the Re-1 and Re-5 commercial vaccines in ducks against H5N1 HPAI clade 2.3.2.1 viruses, and underscore the importance of monitoring vaccine efficacy in the control of H5N1 HPAI in ducks.

Effect of species, breed and route of virus inoculation on the pathogenicity of H5N1 highly pathogenic influenza (HPAI) viruses in domestic ducks

H5N1 highly pathogenic avian influenza (HPAI) viruses continue to be a threat to poultry in many regions of the world. Domestic ducks have been recognized as one of the primary factors in the spread of H5N1 HPAI. In this study we examined the pathogenicity of H5N1 HPAI viruses in different species and breeds of domestic ducks and the effect of route of virus inoculation on the outcome of infection. We determined that the pathogenicity of H5N1 HPAI viruses varies between the two common farmed duck species, with Muscovy ducks (Cairina moschata) presenting more severe disease than various breeds of Anas platyrhynchos var. domestica ducks including Pekin, Mallard-type, Black Runners, Rouen, and Khaki Campbell ducks. We also found that Pekin and Muscovy ducks inoculated with two H5N1 HPAI viruses of different virulence, given by any one of three routes (intranasal, intracloacal, or intraocular), became infected with the viruses. Regardless of the route of inoculation, the outcome of infection was similar for each species but depended on the virulence of the virus used. Muscovy ducks showed more severe clinical signs and higher mortality than the Pekin ducks. In conclusion, domestic ducks are susceptible to H5N1 HPAI virus infection by different routes of exposure, but the presentation of the disease varied by virus strain and duck species. This information helps support the planning and implementation of H5N1 HPAI surveillance and control measures in countries with large domestic duck populations.

Susceptibility of avian species to North American H13 low pathogenic avian influenza viruses

Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemagglutinin subtypes (H13 and H16) are rarely detected in other avian groups, and existing surveillance data suggests they are maintained almost exclusively within gull populations. In order to evaluate the host range of these gull-adapted influenza subtypes and to characterize viral infection in the gull host, we conducted a series of challenge experiments, with multiple North American strains of H13 LPAI virus in ring-billed gulls (Larus delawarensis), mallards (Anas platyrhynchos), chickens (Gallus domesticus), and turkeys (Meleagris gallopavo). The susceptibility to H13 LPAI viruses varied between species and viral strain. Gulls were highly susceptible to H13 LPAI virus infection and excreted virus via the oropharynx and cloaca for several days. The quantity and duration of shedding was similar between the two routes. Turkeys and ducks were resistant to infection with most strains of H13 LPAI virus, but low numbers of inoculated birds were infected after challenge with specific viral strains. Chickens were refractory to infection with all strains of H13 LPAI virus they were challenged with. The experimental results presented herein are consistent with existing surveillance data on H13 LPAI viruses in birds, and indicate that influenza viruses of the H13 subtype are strongly host-adapted to gulls, but rare spill-over into aberrant hosts (i.e., turkeys and ducks) can occur.

High-precision soft x-ray polarimeter at Diamond Light Source

The development and performance of a high-precision polarimeter for the polarization analysis in the soft x-ray region is presented. This versatile, high-vacuum compatible instrument is supported on a hexapod to simplify the alignment with a resolution less than 5 μrad, and can be moved with its own independent control system easily between different beamlines and synchrotron facilities. The polarimeter can also be used for the characterization of reflection and transmission properties of optical elements. A W/B(4)C multilayer phase retarder was used to characterize the polarization state up to 1200 eV. A fast and accurate alignment procedure was developed, and complete polarization analysis of the APPLE II undulator at 712 eV has been performed.

The use of hinged external fixation to provide additional stabilization for fractures of the distal humerus

OBJECTIVE

To assess improvements in fixation stability when a hinged unilateral external fixator is used to supplement compromised internal fixation for distal humerus fractures.

METHODS

Removing a 1-cm section of the distal humerus in cadaveric whole-arm specimens created a comminuted distal humerus fracture model (AO type 13-A3). Fixation was then performed using different constructs representing optimal, compromised, or supplemented internal fixation. Internal fixation consisted of either 2 reconstruction plates with 1, 2, or 3 (optimal) distal attachment screws, or crossing medial and lateral cortical screws. A hinged external fixator was applied in combination with compromised internal fixation. The stability of the different constructs was then evaluated using 3-point bending stiffness and distal fragment displacement measurements during flexion and extension testing.

RESULTS

Addition of the external fixator increased the stiffness of all constructs. Stiffness of the compromised reconstruction plate constructs with supplemented fixation was similar to or significantly greater than that of optimal internal fixation. Addition of the fixator to the reconstruction plates with 1 screw or the crossing screws produced displacements of the distal fragment that were similar to those of the compromised constructs alone. However, medial/lateral and anterior/posterior displacements of the distal fragment during flexion and extension of the elbow for supplemented fixation were found to be greater than those for optimal internal fixation.

CONCLUSIONS

The use of a hinged external fixator for supplemental fixation of distal humerus fractures may be effective in cases where internal fixation is severely compromised, although displacements may increase above optimal fixation.

Effect of rapamycin on the healing of the bile duct

Besides its potent immunosuppressive properties, rapamycin also has antitumor and antifungal effects. Rapamycin also inhibits the proliferation of fibroblasts and therefore may impair the healing of various tissues. We investigated the effect of rapamycin on the healing of the bile duct anastomosis. The study was undertaken in pigs that were subjected to a laparotomy under general anesthesia. The bile duct was mobilized and divided and immediately reanastomosed. The animals were randomly allocated to receive either rapamycin or placebo. The animals were sacrificed on the postoperative day 5, then the biliary anastomosis was excised and used to determine the tensile strength, hydroxyproline levels, and the histological changes. The tensile strength and the hydroxyproline levels in the biliary anastomosis were lower in the animals treated with rapamycin. The liver function tests were normal. These studies show that rapamycin may impair the healing of the biliary anastomosis.

Restoration of liver mass after partial hepatectomy--implications for living donor liver transplantation

In living donor liver transplantation, the recipient liver undergoes more rapid regeneration than the remnant liver in the donor. In this study we investigated the factors which may be responsible for the difference in the regenerative response between the donor and the recipient. Long Evans rats were subjected to either partial hepatectomy (PH) or sham operation (SH) and were treated with liver cytosol (C) and cyclosporine (Cy). The rats were sacrificed at 24, 48, 72 and 96 hours and 1 and 2 weeks postoperatively. The livers were removed to determine the liver weight/body weight (LW/BW) ratio and the mitotic index. The mitotic index, serum aspartate transferase (AST) and serum alanine transferase (ALT), although unchanged in the SH groups, were increased in the rats treated with PH + C + Cy, and were greater than after PH only. However LW/BW ratios increased after PH but had returned to preoperative levels by 2 weeks. The changes in LW/BW ratio were not modified by the cytosol or cyclosporine.

The Effect of Rapamycin on the Healing of the Ureteric Anastomosis and Wound Healing

Rapamycin is a potent immunosuppressive agent that also inhibits fibroblastic activity and therefore may affect the healing of various tissues. The aim of this study was to investigate the effect of rapamycin on wound healing and the healing of the ureteric anastomosis. Large White/Landrace pigs were subjected to a laparotomy and division and immediate anastomosis of the ureter. The animals were randomly allocated to receive either rapamycin or placebo. The animals were sacrificed on postoperative day 5, and strips of the skin and fascia closure and the ureteric anastomosis excised and used to determine the tensile strength, hydroxyproline levels, and histological changes. The tensile strength and the hydroxyproline levels in the ureter and fascia were lower in the rapamycin-treated animals. There was no difference in the tensile strength in the skin, although the hydroxyproline levels were lower. This study shows that healing of the ureteric anastomosis and fascia and skin closure may be impaired by rapamycin.

A placebo-controlled study of guanfacine in the treatment of children with tic disorders and attention deficit hyperactivity disorder

OBJECTIVE

This study evaluated the efficacy and safety of guanfacine in treating children with tic disorders and attention deficit hyperactivity disorder (ADHD).

METHOD

Subjects from a specialty tic disorders clinic were randomly assigned to receive 8 weeks of treatment with guanfacine or placebo under double-blind conditions. Follow-up visits occurred every 2 weeks for safety monitoring and dose adjustment.

RESULTS

Thirty-four medication-free subjects (31 boys and three girls with a mean age of 10.4 years) with ADHD, combined type, and a tic disorder participated. After 8 weeks of treatment, guanfacine was associated with a mean improvement of 37% in the total score on the teacher-rated ADHD Rating Scale, compared to 8% improvement for placebo. Nine of 17 subjects who received guanfacine were blindly rated on the Clinical Global Improvement scale as either much improved or very much improved, compared with none of 17 subjects who received placebo. The mean score on the parent-rated hyperactivity index improved by 27% in the guanfacine group and 21% in the placebo group, not a significant difference. On the Continuous Performance Test, commission errors decreased by 22% and omission errors by 17% in the guanfacine group, compared with increases of 29% in commission errors and of 31% in omission errors in the placebo group. Tic severity decreased by 31% in the guanfacine group, compared to 0% in the placebo group. One guanfacine subject with sedation withdrew at week 4. Guanfacine was associated with insignificant decreases in blood pressure and pulse.

CONCLUSIONS

Guanfacine appears to be a safe and effective treatment for children with tic disorders and ADHD.